Rotary hydraulic pump



Jan. 1'3, 1953 c.-J. coBERLY ROTARY HYDRAULIC PUMP 4 sheets-sheet 1Filed Dec. 20. 1948 Jan. 13, A1953 c. J. COBERLY ROTARY HYDRAULIC PUMPFiled oe. 2o, 194e 4 Sheets-Sheet 2 f Vl n m 55% 5, RON im dvr mim@ Wwf,fi@ u Q HAP/5 5y Jan. 13, 1953 c. J. coBERLY l 2,625,109

ROTARY HYDRAULIC PUMP Filed Deo. 20, 1948 4 Sheets-Sheet 5 d//Y ./A uw;

Jan. 13, 1953 c. J. coBERLY 2,625,109

ROTARY HYDRAULIC PUMP Filed Dec. 20, 1948 4 Sheets-Sheet 4 Patented Jan.13, 1953 ROTARY HYDRAULIC PUMP Clarence J. Coberly, Los Angeles, Calif.,assigner, by mesne assignments, to Dresser Equipment Company, Cleveland,Ohio, a corporation of Ohio Application December' zo, 194s, serial No.66,158

25 claims. (C1. 10s- 44) My invention relates to fluid-operated pumpsand, more particularly, to a rotary type of such pump.

The `present invention is of particular utility when used as a well pumpin the oil industry and, consequently, will be described in connectionwith such use, but it is to be understood that I do not desire vorintend to be limited thereto.

Conventional fluid-operated well pumps used in the oil industry includea duid-operated motor having a reciprocating motor piston therein and asingle or double acting pump piston mechani cally connected to the motorpiston, operating fluid under high pressure being supplied to the motorpiston .by a suitable main valve so as to reciprocate the motor piston.The main valve of such a pump is either hydraulically or mechanicallyreciprocated in direct response to reciprocation of the pistons.

A primary object of the present invention is to provide a novelhuid-operated pump having a rotatable rotor unit containing one or morereciprocating pistons, the rotation of the rotor-actuating valve meansto control the ow of fluid to and from the pistons. I prefer toaccomplish this by utilizing the rotor as a rotatable valve member forcontrolling the flow of iiuid, and this is a further object of theinvention.

.Another object of the invention is to provide such a novelduid-operated pump which includes such va rotor and which is capable ofpumping against high pressures.

. Still another object of the invention is to prof vide such afluid-operated pump which employs a stationary cam plate for convertingreciprocating motion of the pistons into rotary motionv of the rotor.

. A further object of the invention is to provide such a fluid-operatedpump in which the cam plate is used to rotate the rotor carrying thepistons, power applied to the motor piston area being transmitteddirectly to the pump pistonarea during the working stroke without usingthe cam plate for the transmission of such power. I also prefertoutilize the cam plate to cause the return stroke of the pistons, whichis another object of my invention.

Another object of the invention is to provide such a novel pump having aplurality of pistons carried by the rotor, `each of the pistons beingrotated upon its own axis during rotation of the rotor so as to reducesliding friction of the pistons in theil` cylinders and to equalize wearthereon.

Another object of the invention i-s to provide such'a novel pump inwhich the rotor co-operates with a stationary valve of fluid to and fromthe pistons.

A still further object of the invention is tc provide such a novel pumpin which the pumping stroke oi the pump piston area is caused byapplying operating fluid under pressure to the motor piston area and inwhich return stroke Lof the pistons is produced 'by the rotation of therotor relative to the cam plate.

Another object is to provide such a pump in which the operating iiuidlubricates the relatively moving parts thereof.

A further object of the invention is to provide such a pump .with arotary valve which operates in timed relation to the position of therotor and pistons to control the intake and discharge of both the motorand the pump.

Another object is to provide such a pump including a rotor and a valveplate in which a hydraulic balance is provided therebetween to eliminateor control end thrust of the rotor against the Valve plate.

Still another object of the invention is to provide such a pump having acombined valve for the motor intake and dischargeand the pump intake anddischarge, in which a diierential fluid pressure on the pump pistontimes the effective pump port area is equal and opposite to a dif-vferential fluid pressure on the motor piston times the effective motorport area.

Another object of the present invention is to provide a fluid-operatedpump of the character hereinbefore described which may be used eitheralone or in multiple to'obtain the desired pump ing capacity.

Another object is to provide such av pumping device including aplurality of fluid-operated pump units of the character hereinbefore setforth and having separate inlets for conveying fluid to be pumped to theinlet ports of the respective units. Y Another object in connection withone embodiment of the invention is to provide such a pumping devicehaving'an outlet for the spent operating fluid and pumped fluid which iscommon to all of the fluid-operated units.

Still another object is to provide a. pumping device in which two ormore fluid-operated pump units of the invention are connected in tandemand in which operating fluid for the motor of each succeeding unit inthe series passes through the preceding unit in the series.

Another object is to provide a piston plunger having a major areacontinuously exposed to -pump discharge' pressure, a minor areaalterplate to control the ilo nately exposed to pump intake pressure andto pump discharge pressure, and an annular area Ialternately exposed tooperating iiuid pressure and to pump discharge pressure.

The foregoing objects and advantages of the invention, together withvarious other objects and advantages thereof which will become apparent,may be attained through the employment of the exemplary embodiments ofthe invention which are illustrated in the accompanying drawings andwhich are described in detail hereinafter. Referring to the drawings:

Fig. 1 is a diagrammatic utility view showing a {duid-operated pumpingdevice embodying the invention as installed in a Well;

Fig. 2 is an enlarged longitudinal sectional view of the upper end ofthe invention;

Fig. 3 is a longitudinal sectional view of an intermediate portion ofthe invention and is a downward extension of Fig. 2;

Fig. 4 is a longitudinal sectional view of the lower end of theinvention and is a downward extension of Fig. 3;

Figs. 5, 6, 1 and 8 are transverse sectional views respectively takenalong the broken lines 5-5, 6-6, 1--1 and 8-8 of Fig. 3;

Fig. 9 is a longitudinal sectional view which is similar to Fig. 3 butwhich illustrates the upper end of another embodiment of the invention;

Fig. l is a longitudinal sectional View of the embodiment illustrated inFig. 9 and is a downward extension of Fig. 9; and

Figs. l1 to l5 are transverse sectional views respectively taken alongthe broken lines to ||5 of Fig. 9.

Referring particularly to Fig. 1 of the drawings, I show a casing set ina well and extending into an oil-producing formation 3| of the well, thecasing being perforated, as indicated at 32, to admit oil and otheruids, such as gas, water and the like, into the casing from theoil-producing formation. Extending into the well casing 30 and supportedby a casing head 33 are power and production tubings 34 and 35, thelatter being lconnected at their lower ends by a fitting 36. Connectedto the lower end of the fitting 36 is a tubular receiver 31 for afluid-operated pump 38 of the invention, the receiver being aligned withand1 in effect, forming an extension of the tubing 34 in the particularconstruction illustrated. Connected to the lower end of the receiver 31is a fitting 39 through which uid is admitted from a body 40 of fluid inthe well casing 3U.

Considering the general operation of the apparatus as thus fardescribed, an operating fluid, Such as clean crude oil, is deliveredunder pressure to the pump 38 through the power tubing 34 to operate thepump as will be described in more detail hereinafter. The well fluidentering the receiver 31 through the fitting 39 is discharged into theproduction tubing by the pump 38 and flows upwardly through theproduction tubing to the surface. Operating fluid may be delivered tothe power tubing 34 by any suitable apparatus (not shown) as is wellknown in the art.

In the particular application of my yinvention illustrated in thedrawings, the .power and production tubings 34 and 35 are arranged sideby side and the pump 38 is of the so-called free type so that it may bepumped into and out of the well as is well known in the art and as willbe discussed in more detail hereinafter. Any suitable valve controlapparatus for controlling the Iiow of power oil to pump the pump 38 intoand out of the well may be employed. For example, such a controlapparatus may comprise a fluidoperated pump head such as that disclosedin my Patent No. 2,338,903, issued January 11, 1944.

It will be understood that the present invention is not to be regardedas limited to application to an apparatus such as that hereinbeforedescribed since it is susceptible of various other applications as willbe apparent to those skilled in the art. For example, the invention isnot limited to application to a free pump such as the pump 38 and may beembodied in a fixed pump for well pumping purposes if desired. Also, theinvention is not limited to the particular tubing arrangement shown.

Considering in more detail the illustrative embodiment of the inventionwhich is illustrated in Fig. 1 of the drawings, the tting 36 connectingthe lower ends of the power and production tubings 34 and 35 to the pumpreceiver 31 is, as best shown in Fig. 3 of the drawings, provided with abore 4| therethrough into which the power tubing and the tubularreceiver are threaded, the power tubing being threaded into the upperend of the bore 4| and the receiver being threaded into the lower endthereof. Disposed in the bore 4| is a liner 42 having an internaldiameter slightly less than the internal diameters of the power tubing34 and the tubular receiver 31. The lower end of the production tubing35 is threaded into a bore 43 in the fitting 35 and communicating withthe bore 43 is a lateral passage 44 which terminates in an annulargroove 45 formed in the fitting 36 and encircling the line 4Z, thelatter having a plurality of radial openings 45 therein whichcommunicate with the annular groove 45 and which perform a function tobe discussed hereinafter. Referring now to Fig. 4 of the drawings, theinlet fitting 39 is threaded on the lower end of the tubular receiver 31and is provided with an annular, internal shoulder which supports acollar 41, the latter providing a tapered seat for an externally taperedpump seat member 48. The member 48 provides a tapered seat 49 for theduid-operated pump 38. Threaded onto the lower end of the pump seatmember 48 is an inlet fitting 5U which carries a check valve 5| forpreventing outflow. Connecting the lower end of the bore 43 in thefitting 36 with a bore 52 1n the fitting 39 is a tube 53, the bore 52being connected to a space 54 below the pump 38 by a port 52a so thatthis space is exposed to fluid pressure in the production tubing 35 fora reason to be discussed hereinafter.

Referring to Figs. 3 and 4, the fluid-operated pump 38 includes an upperpump unit 55 and a lower pump unit 56 disposed in tandem. The two pumpunits 55 and 56 are of similar construction s0 that only the upper pumpunit 55 will be described in detail. The pump unit 55 includes a camiitting 51 at its upper endl a valve ntting 58 at its lower end,connected together in spaced relation by a tubular shell 59, and acylinder barrel or rotor 6D rotatably mounted upon a tubular shaft 6|.

The cam fitting 51 is disposed in the liner 42 opposite the radialopenings 46 therein when the pump is in its operating position in thetubular receiver 31. The cam fitting 51 makes a sliding t with the liner42 and carries means for providing Huid-tight seals on either side ofthe radial openings 46 in the liner, the sealing means being exemplifiedas a pair of O-rings. The cam fitting 51 is provided at its lower end 5.with a portion of reduced diameter onto which the tubular shell 59 isthreaded, this shell providing a chamber 62 from which the cylinderbarrel 60 is spaced to provide an annular space 03 therebetween. Thelower end of the tubular shell 59 is threaded onto the upper end of thevalve fitting 58. Threaded into the upper end of the cam fitting 51 is apressure inlet member 84 having an axial bore 85 and provided withradial ports 68 which communicate with the interior of the power tubing34. Threaded into the inlet member 64 and extending upwardly therefromis a two-piece stem 61 having resilient expansible packing cups 68thereon, as shown in Fig. 2.

rAs shown in Fig. 3, the cam tting 51 is provided with an axial bore 69which communicates at its upper end with the bore 65 and at its lowerend with a counterbore 10. Also provided in the cam fitting 51 is alongitudinal discharge passage 1| which communicates at its upper endthrough a radial port 12 with an annular groove 13 which registers withthe radial liner openings 46. The discharge passage 1| communicates atits lower end through a radial port 14 with the upper end of the chamber62. The lower end of the cam fitting 51 is provided with a plane camface 15 which is disposed at an angle to the axis of the cam fitting.

The `cylinder barrel 80 rests upon a valve 11 provided at the upper endof the valve fitting 58, the barrel being rotatably mounted on thetubular shaft 6|. The tubular shaft 6| is provided, adjacent its upperend, with an annular shoulder 18 which rests upon the upper end of thebarrel 60 to prevent longitudinal movement of the tubular shaft. Thetubular shaft is also provided with suitable packing, such as O-rings,adjacent its upper and lower ends so as to form a seal between theexterior of the shaft and the cam fitting 51 and the valve tting 58yrespectively. .As best shown in Fig. 5, the cylinder barrel 60 isprovided with a plurality of circumferentially spaced cylinder bores 19and, although four of such bores are shown in the embodimentillustrated, it is to be understood that more or less may be -employedas desired. Provided in the lower portions of each of such bores 19 is atubular liner 80, the major portion of which is spaced from the wall ofthe bore to provide an annular space 8| therebetween. The lower end ofeach of the liners80 is provided with a longitudinal inlet passage 83,ywhich, as best shown in Fig. 6, is preferably arcuate in form. Theperiphery of each of the liners 80 is also provided with a longitudinalpressure inlet groove 84 which communicates at its upper end with theannular space 8|.

Disposed in each of the cylinder bores 19 is a piston plunger 85, theupper portion 85 of which makes a close-sliding t in the bore 19, thelower portion 81 being of reduced diameter and making a close-slidingfit in the tubular liner 80, the two portions being separated by anannular shoulder 88 forming a high-pressure area. The upper end of eachof the plungers 85 is provided with a bevelled follower face 98 whichengages the cam face 15 of the cam fitting 51, As will be understood,the upper ends of the plungers 85 extend into the chamber 62, formingpumping portions of the plungers.

The valve fitting 58 is provided with an axial bore 92 whichcommunicates at its upper end with an annular groove 93 and acounterbore 94 into which the lower end of the tubular shaft 6.- 6|extends. Formed in the valve fitting 58 and communicating with theannular groove 93 is a plurality of inlet passages 95, all of whichcommunicate at their upper ends with a supply recess 96 formed in thevalve face 11. Also formed in the valve fitting 58 is a plurality ofwell fluid inlet passages 98 which communicate at their upper ends withan arcuate inlet recess 99 formed in the Valve face 11. The lower endsof each of the well fluid inlet passages 98 communicate .through thecorresponding radial port |00 with an annular space |0| provided betweenthe receiver 31 and the tubular shell 59 and valve fitting 58. Alsoprovided in the valve fitting 58 is a plurality of longitudinaldischarge passages |02 which communicate at their upper ends, as shownin Fig. '1, with an arcuate discharge recess |03, and communicate attheir lower ends, as shown in Fig. 4, through individual radial ports I04 with the exterior of the valve tting 58. The lower end of the Valvefitting 58 is provided with a plane cam face |05 which is identical withthe cam face 15 of the cam fitting 51.

As shown in Fig. 4, and as indicated above, the lower pump unit 55 issubstantially identical with the upper pump unit 55, including acylindrical barrel |01, a lower barrel fitting |08, and a tubular shell|09 connecting the lower Valve fitting with the valve fitting 58.Connected to the lower end of the lower valve fitting |08 is a pumpinlet member H0, the lower end of the bore of the lower valve fitting|08 being closed by a plug ||2 disposed between the lower valve fittingand the pump inlet member. The pump inlet member H0 is provided with anaxial inlet bore H4 and a plurality of radial passages |I5 connectingthe bore with a space |0| around the exterior of the duid-operated pump38. The lower' end` of the pump inlet member |0 is provided with aseating space H8 adapted to seat on and form a fluid-tight seal with thetapered seat 49. Suitable packing I l1 is provided on the periphery' ofthe pump inlet member H0 so as to form a fluid-tight seal between thepump inlet member and a liner collar |I8 welded or otherwise secured inthe lower end of the receiver 31. As will be noted, the liner collar ||8serves to space the fluid-operated pump 38 from the receiver 31.

1n operation, high-pressure operating fluid, such as clean crude oil, isconveyed downwardly through the power tubing 34 past the packing cups 58and through the radial ports of the pressure inlet member 84 into thefluid-operated pump 88. Such operating fluid ows downwardly through theaxial bores 85 and 89 and through the tubular shaft 8| to lthe annulargroove 93 in the valve tting 58.

In the upper pump unit 55, with the parts in the position shown in Fig.3, the left-hand piston plunger 85 is moving downwardly and has almostreached the bottom of its downward stroke, and the right-hand pistonplunger 85 is moving upwardly and has almost reached the top of itsupward stroke. In this position, operating fluid flows from the annulargroove 93 up through the pressure inlet passages 95 to the -supplyrecess 96, and thence upwardly through the longitudinal pressure inletgroove 84 communicating with the supply recess, and through the annularspace 8| to the shoulder 88 on the right-hand piston plunger 85. Suchapplication of operating fluid to the annular shoulder 88 of theright-hand piston plunger 85 causes it to continue its upward strokeuntil its follower face` 90 lpasses over the highest point on the .camface 15. As the right-hand piston plunger 85 moves upwardly, its upperportion 86 occupies an increasingly greater volume in the chamber 62thus displacing fluid therefrom upwardly through the radial port 14, thelongitudinal discharge passage 1I, the radial ports 12, the radialopenings 46, the annular groove 45, the lateral passage 44, and into thebore 43 of the fitting 36, whence it flows upwardly throughtheproduction tubing 35 to the surface of the ground. It will thus beappreciated that the upstroke of each of the plungers 85 constitutes thepumping stroke thereof, being caused by the application of operating uidunder relatively high pressure to the pressure area provided by theannular shoulder 88.

During the upstroke, or pumping stroke, of the right-hand piston plunger85, as seen in Fig. 3. the lower end thereof performs a suction stroke.Thus, as the piston plunger moves upwardly it draws well fluid throughthe check valve upwardly through the inlet bore H4 and through theradial passage H5 into the annular space |0| through which it flowsupwardly and through the radial ports Il, flowing up through the inletpassages 98, the arcuate recess 99, and the inlet passage 83 into thetubular liner below the piston plunger.

Upward movement of the right-hand piston plunger 85, as seen in Fig. 3,in engagement with the cam face exerts a rotational force upon thecylinder barrel EQ, causing it to rotate on the tubular shaft 5|. As theright-hand piston plunger 85 passes the highest point on the cam face15, rotation of the cylinder barrel S0 moves the pressure inlet grooveS4 of that piston plung er out of registry with the supply recess 96 inthe valve face l1, thus shutting off the flow of operating fluid to thatpiston plunger. Continued rotation of the cylinder barrel 50 then causessuch pressure inlet groove 84 of that piston plunger 85 to register withthe discharge recess |03, and spent operating fluid can then flow frombelow the shoulder 8S of that piston plunger through the annular space8|, the inlet groove S4, the discharge recess |03 and one of the radialports ltd. into the annular space 53 and to the chamber E2. At the sametime that the inlet groove 8d registers with the discharge recess |13,the inlet passage 83 also registers with the discharge recess to permitdisplacement if well fluid from below the piston plunger 85. Continuedrotation of the barrel 6) causes the piston plunger 85 to movedownwardly on its return stroke from the highest to the lowest point onthe cam face l5, the angle of the cam face and the rotation of thebarrel causing such return stroke. As will be noted, the duid in thechamber 62 is always at substantially the same fluid pressure as existsin the production tubing 35, and, as during the downstroke of the pistonplunger 85, the annular shoulder 88 and its lower end are both in fluidcommunication with the chamber 62, during the downstroke of the pistonplunger the hydraulic pressures thereon are substantially balanced.During the down or return stroke of the piston plunger 85, spentoperating fluid is expelled by the annular shoulder 88 through theannular space 8| and the inlet groove 84 into the discharge recess ID3and thence through the annular space 63 into the chamber B2. At the sametime, well iiuid is expelled from below the piston plunger 85 throughthe inlet passage 83 into the discharge recess |03 where it mingles withthe spent operating fluid, and thence through the Vspace 83 v into thechamber 62. The down or return stroke of the piston plunger 85 thusrequires only enough power to overcome friction between the pistonplunger and the cam face 15, and between the piston plunger and itscylinder bore 13, and the fluid friction required to displace the spentoperating iluid and well fluid therebelow into the chamber 62, and,since the piston plunger is substantially hydraulically balanced, itrequires only little power to perform its return stroke. No pumpingaction occurs on the downstroke of the piston plunger S5, the spentoperating fluid and well fluid therebelow merely being displaced intothe chamber 62.

After the right-hand piston plunger 88 asvseen in Fig. 2, passes thehighest point on rthe cam face 15. it, of course, exerts no furtherturning moment on the cylinder barrel |30, continued rotation of thebarrel being caused by the upstroke of one of the other pistons 85moving from the lowest point to the highest point on the cam face, thepiston plungers operating sequentially to maintain rotation of thebarrel.

As the right-hand piston plunger 85 moves to the lowest point on the camface 15, rotation of the barrel 60 causes its inlet passage 83 and itsinlet groove 84 to move out of registry with the discharge recess `|53and again with registry with the recesses 99 and 96, respectively, tocommence another cycle of operation of that piston plunger. All of thepiston plungers 85, of course, operate in identically the same mannerbut sequentially. Each piston plunger 85 on its upstroke, or pumpingstroke, displaces a volume of fluid from the chamber 62 upwardly throughthe production tubing 35. Upon its downstroke, the spent operating uidand well fluid below the piston plunger 85 are displaced into thechamber G2, the volume of such displaced operating and well iiuid beingequal to the volume of iiuid displaced from the chamber 62 on thepumping stroke. With four or more piston plungers 85, the discharge intothe production tubing 35 is at a substantially constant rate. Although Ihave, for convenience of illustration, shown only four piston plungers35, in practice l' prefer to use five or seven thereof so as to smoothout the operation of the device.

It is to be noted that as the cylinder barrel 60 rotates `upon its axis,each of the piston plungers 85 also rotates upon its own axis, due toengagement of its cam follower face 93 with the cam face 15, and this isan important feature of the invention as it reduces friction andequalizes wear on the piston plungers. It is also to be noted that inthis invention each of the piston plungers 85 serves as both a pump andengine on its upstroke, the application of power being directly from theengine to the pump portions of the plunger and no pumping power beingtransmitted on the upstroke through the cam face l5, and this is afurther important feature of the invention. In fact, the only functionof the cam face 15 is to rotate the cylinder barrel 60 to control thevalve means of the pump unit and to cause the return stroke of eachpiston plunger.

It will also be understood that by the construction described I providea combined valve mechanism for the engine intake and dischargecontrolling the flow of operating iluid to and from the pressure areaprovided by shoulder 88, and for the pump intake and discharge. Therecesses 96, 99 and |03 are so proportioned as to area and leakagetherebetween as to eliminate end thrust on the cylinder barrel Bntending to separate it from the valve face 11 or in the oppositedirection so as to increase the rotational friction therebetween, thehydraulic pressures on the cylinder barrel being substantially balanced.Hydraulic balancing of the cylinder barrel El! may be attained by makingequal the net upward and downward forces applied thereto, the netdownward force being equal to the difference between the dischargecolumn pressure and the well pressure times the effective area of thepump inlet recess 99, and the net upward force being equal to thedifference between the operating fluid pressure and the discharge columnpressure times the effective area of the engine supply recess 96. Due tothe fact that some fluid will flow from the recess 96 to the recess 99,the effective areas of these recesses are somewhat greater than theactual areas thereof.

The operation of the lower pump unit a is videntical with that of theupper pump unit 55,

as described above, and need not be described in detail. Operating fluidflows to the lower pump unit 56 through its tubular shaft similar to theshaft 6|, and spent operating fluid and well fluid therefrom flowupwardly through the longitudinal discharge passages |02 into thedischarge recess |93 of the valve fitting 58, where they mingle with theflow from the upper pump unit 55. The pump units 55 and 55 are thus intandem and operate simultaneously. It will also be noted that the lowervalve fitting |08 of the lower pump unit 56 is identical with the valvefitting 5B of the upper pump unit 55, thus permitting an additional pumpunit (not shown) to be connected in tandem below the lower pump unit 55.Although two pump units 55 and 55 are shown connected in tandem, it willbe apparent that one or more of such pump units may be employed asrequired, to provide a desired total pumping capacity for thefluid-operated pump 38.

vAn alternative embodiment of the invention is shown in Figs. 9 to 15 ofthe drawings, including a fluid-operated pump |3|) which is generallysimilar to the previously described fluid-operated pump 38, the pump |30being shown oberatively positioned in a tubular receiver 31a. Thefluid-operated pump |30 includes only a single pump unit for convenienceof illustration so that, in the present embodiment, the tubular receiver31a is correspondingly shorter. However, in all other respects, thetubular receiver 31a and the parts connected lthereto are identical tothe corresponding parts of the previously described embodiment and areidentified by the same numerals with the suflix a added thereto.

As will be understood, although I have elected to show thefluid-operated pump |30 as including but a single pump unit, any numberof such pump units may be connected in tandem as hereinbefore discussed.

The fluid-operated pump |30 includes a fitting.

51a having a tubular shell 59a threaded onto the lower end thereof toprovide a chamber 62a, and threaded onto the lower end of the shell is avalve fitting 58a. The valve fitting 58a is generally similar to thevalve fitting 58 of the previous embodiment, the lower surface of whichis adapted to serve as a cam for another pump unit (not shown).

Threaded onto the lower end of the valve fitting 58a is a pump inletmember lita for the pump |30, which is adapted to engage the taperedseat 49a provided by the pump seat member 48a in the fitting 39a. Thevalve fitting 58a is provided with an axial bore therethrough which isclosed at its lower end by the plug ||2a on the pump inlet member Illia.Y

Extending axially of the chamber 62a is a tubular shaft Gia, the ends ofthis shaft being disposed n the counterbores 10a and 94a and beingsuitably sealed with respect to the fitting 51a and being splined orotherwise locked with re"- spect to the fitting 58a. The interior of thetubular shaft Gla communicates with the power tubing 34a through theaxial bore 69a in the fitting 51a, the axial bore 65a in the pressureinlet mem'- ber 54a and the radial openings 12a therein.

Rotatably mounted on the tubular shaft 6| a is a cylinder barrel 60a,the barrel having a plurality of cylinder bores 19a therein which areopen at their upper ends. Reciprocable in` and projecting from the upperends of the cylinder bores 19a are piston plungers 85a. Each pistonplunger 85a is provided at its upper end with a cam follower face 90awhich is complementaryt'o the cam face 15a. Each piston plunger 85a isalso provided with an annular shoulder 88a.

As best shown in Figs. 9 and 11, the external surface of the tubularshaft Sla is provided with a semi-annular intake groove |3| which isconnected to the interior of the tubular shaft by va radial port |32.The cylinder barrel 60a ispro- 4vided with a plurality of radial motorports V|33 which communicate with the lower'ends vof the respectivecylinder bores 19a and which are adapted to register in seouence withtheintake groove |3| to admit operating fluid under pressure sequentiallyinto the cylinder bores. As in the case of the previously describedembodiment, the intake groove |3| is of such length and is so positionedwith respect to the cam face 15a that operating fluid under pressure isadmitted into the cylinder bore 19a during the interval that the camfollower faces 90a on the corresponding piston plungers 85a are inengagement with the rise of the cam face 15a.

Diametrically opposite the intake groove |3| in the external surface ofthe tubular shaftfla is an exhaust groove |34 with which the motor ports|33 are adapted to register in sequence to discharge spent operatingfluid from the cylinder bores 19a during the downstroke of the pistonplungers a. The exhaust groove |34 communicates with the chamber 62a byway of a longitudinal groove |35 in the external surface of the tubularshaft 6 la. Thus, the tubular vshaft Sla and the cylinder barrel 69aserve as a valve means for controlling intake and exhaust of operatingfluid into and from the cylinder bores 19a, each cylinder bore receivinga charge of operating fluid under pressure during the upstroke of thecorresponding piston plunger 85a, and such charge of operating fluidafter it is spent being discharged therefrom during the downstroke ofthe corresponding piston plunger.

As best shown in Figs. 9 and 14, the upper end of the valve fitting 58ais provided with an arcuate inlet recess 99a which is adapted to receivewell fluid to be pumped from the annular space |0|a within the tubularreceiver 31a through radial inlet passages |00a and longitudinal inletpassages 98a. 'Ihe lower ends of the cylinder bores 19a are adapted toregister with the arcuate inlet recess 99a in sequence during rotationof the cylinder barrel 60a to admit well fluid to be pumped into thelowerendsof the cylinder bores. As in the previously describedembodiment, the

arcuate inlet recess 99a is so located that the cylinder bores 19aregister therewith during the upstroke. of. the corresponding pistonplungers 85a.

Also formed in the top of the valve fitting 58a is an arcuate outletrecess |0311 with which the lower ends of the cylinder bores '19a areadapted to register n sequence to permit the discharge of pumped wellfluid from the bores. The outlet recess |D3a is so positioned withrespect to the cam face, 15a that the lower ends of the cylinder bores19a register therewith during the downstroke of the corresponding pistonplungers 85a.

In the particular construction under consideration, the outlet recess03a communicates with the chamber 52a surrounding the cylinder barrel60a through radial ports. |04a so that the pumped well. fluidandthespent operating duid are mixed in the chamber 62a and flowtherefrom into the production tubing a through the previously describedconnecting passages. It will be understood, however, that if mixing ofthe pumped well fluid; and expended operating fluid is not desired, theoutlet recess |0311. may be. connected to a separate tubing (not shown).

Referring to Figs. 9 and 11, the interface between the tubular shaft 6la and the cylinder barrela is lubricated by operating fluid through aradial port |36 and a groove |31 in the external surfaceof the tubularshaft. If desired, the interfacebetween the tubular` shaft 6-|a and thecylinder barrel 60a may be lubricated at a plurality of. axially spacedpoints in this manner. Lubrication of the piston plungers 85a isaccomplished by providing connected longitudinal and transverse passages|38- and |39, respectively, in the piston plungers, each longitudinalpassage |38 communicating with the chamber 62a surrounding the cylinderbarrel 60a so that fluid may flow from the chamber through thelongitudinal and transverse passages to lubricate the piston plungers.The operation of the fluid-operated pump |30 s similar to that of thefluid-operated pump 38 and` it. isy thought that a further descriptionof the operation of the pump |30 is unnecessary.

Thek cylinder barrel 60a is substantially hydraulically balanced in theaxial direction by admitting operating fluid into an annular recess Illvin the top of the valve tting 58a around the tubular shaft Sla, theoperating fluid being admitted into this recess by wayy of the splinedconnection between the valve fitting and the tubular shaft. The annularrecess |.4I is of such a size that the operating fluid therein appliesan upward force to theA barrel 60a. substantially equal to the.difference between the downward force applied4 thereto. by the fluidmixture in the chamber 62a and the upward forces applied thereto by thefluid inthe recesses 99a and. 03a.

It willl be noted that the aforementioned axial forcesapplied to thecylinder barrel 65a are not coaxial, so that a turning moment tending todisplaceY the barrel about an axis normal to its axis of rotation isapplied thereto. Also, the operating. fluid in the groove |3| applies a.lateral forceV to the cylinder barrel which is only partiallycompensated by the fluid in the diametrically opposite exhaust groove|34. These conditions arer compensated for byV the operating fluid inthe groove |31.

Although Iv have disclosed a specific application of myinvention hereinand have disclosed exemplary embodiments thereof for purposes ofillustration, it will be understood that I do not intend to be limitedspecifically thereto since the invention is susceptible of various otherapplications and since various changes, modifications and substitutionsmay be incorporated in the particular embodiments disclosed, all withoutnecessarilyA departing from the spirit of the invention as set forthinthe appended claims.

l claim as my invention:

l. In a fluid-operated pump, the combination of: a chamber; cam means insaid chamber; cylinder means providing at least two cylinders eachhaving an end communicating with said chamber and facing said cam means;piston means in each of said cylinders and extending into said chamberinto engagement with said cam means, said piston means being movableinto` said chamber to displace fluid therefrom, the interaction betweensaid cam means and said piston means upon movement of said piston meansinto said chamber producingk relative rotation between said cam meansand said cylinder means; means for admitting fluid to be pumped intosaid chamber; and means. for alternately connecting the other end ofeach of said cylinders to a sourcev of operating fluid under pressureand to said chamber.

2. in a fluid-operated pump, the combination of: a chamber; cam means insaid chamber; cylinder means providing at least two cylinders eachhaving an end communicating with said chamber and facing said cam means;piston means in each of said cylinders and extending into said chamberinto engagement with said cam means, said piston means being movableinto said chamber to displace fluid therefrom, the interaction betweensaid cam means and said piston means upon movement of said piston meansinto said chamber producing relative rotation between said cam means andsaid cylinder means; means, including valve means responsive to relativerotation between said cam means and said cylinder means,y for admittingfluid to be pumped into said chamber; and valve means responsive torelative rotation between said cam means and said cylinder means foralternately connecting the other end of each of said cylinders to asource of operating fluid under pressure and to said chamber.

3.. In a fluid-operated pump, the combination of: a chamber; stationarycam means in said chamber; a rotor provided with at least two cylinderseach having an end communicating with said chamber and facing said cammeans; piston means in. each cf said cylindersA and extending into saidchamber into engagement with raid cam means, said piston means beingmovablel .into said chamber' to displace fluid therefrom, theinteraction between said cam means and said piston means upon movementof said piston means intoy said chamber producing rotation of said rotorrelative to said cam means; means for admitting fluid to be pumped intosaid chamber; and valve means for alternately connecting the other endof each of said cylinders to a source of operating fluid under pressureand to said chamber.

4. In a fluid-operated pump, the combination of z a chamber; stationarycam means in said chamber; a rotor provided with at least two cylinderseach having an end communicating with said chamber and facing said cammeans; piston means in each of said cylinders and extending into saidchamber into engagement with said cam means, said piston means beingmovable into said chamber to displace fluid therefrom, the interactionbetween said cam means and said I piston means upon movement of saidpiston means into said chamber producing rotation of said rotor relativeto said cam means; means,

including valve means responsive to rotation of said rotor, foradmitting fluid to be pumped .intov said chamber; and valve meansresponsive to rotation of said rotor for alternately connecting theotherend of each of said cylinders to a source of operating duid underpressure and to said chamber.

5. In a fluid-operated pump, the combination of a chamber; a rotor; atleast two reciprocable piston means carried by said rotor and movableinto said chamber to displace duid therefrom, said piston means havingpressure areas thereon which, when exposed to fluid pressure, causemovement of said piston means into said chamber; means for rotating saidrotor; means for moving said piston means out of said chamber; and valvemeans responsive to rotation of said rotor for alternately connectingeach of said pressure areas to a source of operating fluid underpressure and to said chamber.

6. A fluid-operated pump according to claim 3 including means forrotating each of said piston means about its own axis in response torotation of said rotor.

'7. In a fluid-operated pump, the combination of a chamber; cam means insaid chamber; a rotor: at least two reciprocable plungers carried bysaid rotor and each having a pumping end extending into said chamber andadapted to engage said cam means, each of said plungers having anintermediate high-pressure area thereon; means for admitting fluid to bepumped to said chamber; and means for alternately connecting each ofsaid high-pressure areas to a source of operating uid under pressure andto said chamber, the operating fluid under pressure acting on each ofsaid high-pressure areas moving the corresponding plunger toward saidcam means to displace fluid from said chamber, the interaction of saidcam means and said plungers producing rotation of said rotor and saidcam means producing the return strokes of said plungers.

8. A fluid-operated pump according to claim '7, including means forhydraulically balancing the fluid pressures on each of said plungersduring its return stroke.

9. In a duid-operated pump, the combination of: a chamber; cam means insaid chamber; a rotor having at least two plunger cylinders therein eachproviding a major bore and a minor bore, said minor bores being adaptedto communicate with a source of fluid to be pumped; a reciprocableplunger in each of said cylinders having a major portion in said majorbore of such cylinder and a minor portion in said minor bore thereof,said major portion of each plunger extending into said chamber intoengagement with said cam means, the junction of said major and minorportions of each plunger defining a high-pressure motor area and theminor portion of each plunger defining a vsuction area; and valve meansresponsive to rotation of said rotor for alternately connecting eachmotor area and suction area first to said chamber and then to a sourceof operating nuid under pressure and a source of fluid to be pumped,respectively, each of said plungers moving toward said cam means whensaid motor area thereof is connected to a source of operating iiuidunder pressure so as to displace fluid from said chamber, movement of 1said plungers toward said cam means causing I rotation of said rotor toactuate said valve means,

said cam means producing return movement of said plungers.

10. A pump, including: a chamber; at least two cylinders eachcommunicating at one end with said chamber; pistons in said cylinders,respectively, each of said pistons being movable into said chamber todisplace fluid therefrom; valve means for alternately connecting theother end of each of said cylinders to a source of fluid to be pumpedand to said chamber; and means for reciprocating said pistons in saidcylinders.

l1. A pump according to claim 10 wherein said cylinders are formed in arotor and wherein each of said pistons is provided with a high-pressurearea, said pump including: cam means in said chamber and engageable bysaid pistons, the interaction between said pistons and said cam meansproducing rotation of said rotor; and valve means for alternatelyconnecting said high-pressure areas to a source of operating fluid underpressure and to said chamber.

12. A fluid-operated pump, including: a stationary cam having a camsurface; a stationary valve member provided with an intake port, anexhaust'port, and an inlet port therein; a rotor between said camsurface and said valve member, said rotor being rotatable relative tosaid cam and said valve member about an axis which intersects said camand said valve member, said rotor being provided with a plurality ofspaced cylinders which are spaced from and parallel to ysaid axis, saidrotor being provided with a plurality of operating fiuid ports whichrespectively communicate with said cylinders and which are adapted toregister with said intake and exhaust ports in sequence during rotationof said rotor, and being provided with a plurality of pumped fluid portswhich respectively communicate with said cylinders and which are adaptedto register with said inlet and exhaust ports in sequence duringrotation of said rotor; and a plurality of pistons respectivelyreciprocable in said cylinders, each of said pistons having at one endthereof a cam follower which is adapted to engage said cam surface andhaving at the opposite end thereof two transverse pressure surfacesrespectively exposed to fluid pressures obtaining in the correspondingoperating fluid and pumped fluid ports, said cam followers being adaptedto cooperate with said cam surface to convert linear movement of saidpistons under the influence of operating fluid pressure applied theretothrough said operating huid-ports into rotational movement of saidrotor, whereby to move said operating iiuid ports in said rotor intoregistry with said intake and exhaust ports in said Valve member insequence and to move said pumped iiuid ports in said rotor into registrywith said inlet and eX- haust ports in said valve member in sequence.

13. A fluid-operated pump as set forth in claim l2 wherein said rotor isprovided with a transverse end surface in contact with said valve Amember, and wherein said operating fluid and of: a tubular shaft adaptedto receive operating duid under pressure for operating said motor; astationary cam having a cam surface which' encircles said shaft; a.rotor rotatable abouty said shaft adjacent said cam surface and providedwith a plurality of spaced cylinders which are spaced from and parallelto said shaft; a plurality of pistons respectively reciprocable in saidcylinders, each of'said pistons having at one end thereof a cam followerwhich is adapted to engage said cam surface and having at the oppositeend thereof a transverse-pressure surface exposed to fluid pressure inits cylinder; intake valve means for admitting operating fluid underpressure from the interior of said shaft into said motor cylinders insequence; and exhaust valve means for discharging fluid from said motorcylinders in sequence.

16. In a fluid-operated pump, the combination of: means providing aplurality of cylinders; a piston in each of said cylinders and providingfirst and second transverse surfaces facing one end thereof; intakevalve means for admitting uid under pressure to said first surfaces insequence to move said pistons in one direction in their cylinders insequence; means operatively connecting said pistons for moving saidpistons in the opposite direction in their cylinders in sequence; andinlet valve means for admitting a fluid to be pumped to said secondsurfaces in sequence, said inlet valve means operating concurrently withsaid intake valve means.

17. In a fluid-operated pump, the combination of: a rotor providing aplurality of cylinders generally parallel to the axis of rotation ofsaid rotor; a piston in each of said cylinders and providing first andsecond transverse pressure surfaces facing one end thereof; intake valvemeans operable in response to rotation of said rotor for admitting anoperating fluid under pressure to said first pressure surfaces insequence to move said pistons in one direction in their cylinders insequence; and means operatively connecting said pistons for moving saidpistons in the opposite direction in their cylinders in sequence, andfor rotating said rotor in response to movement of said pistons in saidone direction in their cylinders.

18. A fluid-operated pump as defined in claim 17 wherein the means lastdefined includes cam means engageable by said pistons.

19. A fluid-operated pump according to claim 17 including in addition:inlet valve means operf ating concurrently with said intake valve meansand in response to rotation of said rotor for admitting a fluid to bepumped to said second pressure surfaces in sequence; and discharge valvemeans operating in response to rotation of said rotor for dischargingfluid from said cylinders in sequence.

20. In a fluid-operated pump, the combination of stationary cam means; arotatable rotor provided with a cylinder which is spaced from andparallel to the axis of said rotor and which is provided with an openend facing said cam means; a piston reciprocable in said cylinder andprojecting therefrom toward said cam surface, said piston being adaptedto engage said cam means at one end and having at the oppos'te endthereof two transverse pressure surfaces Within said cylinder; intakevalve means for periodically admitting operating fiuid under pressure toone of said transverse pressure surfaces; inlet valve means forperiodically admitting fluid to be pumped to the other of saidtransverse pressure surfaces; and exhaust valve means for periodicallydischarging fluid from said cylinder.

21. In a fluid-operated pump, the combination of: stationary cam means;a rotor rotatable about an axis intersecting said cam means and providedwith a plurality of spaced cylinders which are spaced from and parallelto said axis; a plurality of pistons respectively reciprocable in saidcylinders, said pistons being adapted to engage said cam means and eachhaving first and second transverse pressure surfaces, said pistons bengbiasable toward said cam means by the action of an operating fluid underpressure on said first pressure surfaces thereof so as to bias saidpistons into engagement with said cam means; intake valve means foradmitting operating fluid under pressure to said rst pressure surfacesin sequence; inlet Valve means for admitting fluid to be pumped to said.second pressure surfaces in sequence; and exhaust valve means fordischarging fluid from saidcylinders in sequence.

22. In a fluid-operated motor, the combination of a chamber; cam meansin said chamber; a rotatable rotor; said rotor having a plurality oflongitudinal cylinders therein; a plurality of pistons respectivelyreciprocable in said cylinders, each of said pistons having one endthereof adapted to engage said cam means and having at the opposite endthereof a transverse pressure surface exposed to fluid pressure in itscylinder; intake valve means for admitting fluid under pressure foroperating said pistons in said cylinders in sequence; and exhaust valvemeans for connecting said cylinders to said chamber in sequence so as todischarge fluid from said cylinders into said chamber in sequence.

23. In a fluid-operated pumping device, the combination of: a firstfluid-operated motor and pump having a rotatable combined motor and pumpunit, and first central passage means through the combined motor andpump unit of said first motor and pump for conveying operating fluidthereto; and a second fluid-operated motor and pump having a rotatablecombined motor and pump unit, and a second central passage through themotor and pump unit of said second motor and pump communicating withsaid first passage and adapted to supply operating fluid to said secondmotor and pump, operating fluid conveyed to said second motor and pumppassing through said first motor and pump.

24. In a rotary motor and pump unit adapted to be used in afluid-operated pump, the combination of: a rotary pump barrel having aplurality of cylinder bores therein and circumferentially spaced aboutthe axis of said barrel; a tubular shaft extending through said barreland axially aligned therewith, said barrel being carried by said shaft;a piston plunger in each of said cylinders, each having an end extendingtherefrom and provided with a cam follower face; and means forconnecting said cylinders in fluid communication with the interior ofsaid tubular shaft.

25. In a fluid-operated pump, the combination of: an upper fittinghaving a, cam face on the lower end thereof, and provided with apressure port and a discharge port; a lower fitting having a valve faceon the upper end thereof. and provided With a suction port; a tubularshell connecting said fittings in longitudinally spaced relation; atubular shaft supported by said fittings and extending therebetween, theinterior of said tubular shaft communicating with said pressure port andsaid Valve face; a cylinder barrel rotatably mounted on said shaftwithin said shell, said barrel having a plurality of longitudinalcylinders therein, said barrel engaging said valve face andCIJ-Operating therewith to formvalve meansfor said ports; and a combinedmotor and pump piston in each of said cylinders and adapted to engagesaid cam face to rotate said barrel.

CLARENCE J. COBERLY.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number 18 UNITED STATES PATENTS Name Date De Leeuw May 15, 1928 Pe`nrodFeb. 16, 1932 Fear Jan. 16, 1934 Pigott Dec. 3, 1935 Reader June 3, 1941Baker Mar. 28, 1944 Blasutta Oct. 15, 1946 Beaman et a1 Jan. 25, 1949Mott May 17, 1949

